This invention is generally directed to toner and developer compositions, and more specifically the present invention is directed to toner compositions, including magnetic, single component, and colored toner compositions, and wherein the carrier particles are coated with a low molecular weight wax, such as CERELUBE S363.TM., available from Diamond Shamrock, or with certain polymeric alcohol waxes. In one embodiment of the present invention, the developer is comprised of a toner composition comprised of resin particles, and pigment particles, and carrier particles having present on the surface a low molecular weight wax, such as CERELUBE S363.TM., available from Diamond Shamrock, or certain polymeric alcohol waxes with hydroxyl functionality. There is also provided in accordance with the present invention developers comprised of positively charged toner compositions comprised of resin particles, pigment particles, and charge enhancing additives, and carrier particles with coatings of certain waxes. Furthermore, in another embodiment of the present invention there are provided single component toner compositions comprised of resin particles, and magnetic components such as magnetites. The toner and developer compositions of the present invention are useful in electrostatographic imaging systems, especially those systems wherein blade cleaning of the photoconductive member is accomplished. Moreover, the toner and developer compositions of the present invention enable the photoconductive imaging member present in an imaging apparatus to function for extended time periods, for example, up to 125,000 cycles while eliminating, or minimizing filming of the imaging member.
Developer and toner compositions with certain waxes therein are known. For example, there are illustrated in U.K. Patent Publication 1,442,835, the disclosure of which is totally incorporated herein by reference, toner compositions containing resin particles, and polyalkylene compounds, such as polyethylene and polypropylene of a molecular weight of from about 1,500 to about 20,000 and preferably about 6,000, reference page 3, lines 97 to 119, which compositions prevent toner offsetting in electrostatic imaging processes. The aforementioned waxes may be selected as carrier coatings for the developers of the present invention in embodiments. Additionally, the '835 publication discloses the addition of paraffin waxes together with, or without a metal salt of a fatty acid, reference page 2, lines 55 to 58 . In addition, many patents disclose the use of metal salts of fatty acids for incorporation into toner compositions, such as U.S. Pat. No. 3,655,374. Also, it is known that the aforementioned toner compositions with metal salts of fatty acids can be selected for electrostatic imaging methods wherein blade cleaning of the photoreceptor is accomplished, reference U.S. Pat. No. 3,635,704, the disclosure of which is totally incorporated herein by reference. Additionally, there are illustrated in U.S. Pat. No. 3,983,045 three component developer compositions comprising toner particles, a friction reducing material, and a finely divided nonsmearable abrasive material, reference column 4, beginning at line 31. Examples of friction reducing materials include saturated or unsaturated, substituted or unsubstituted, fatty acids preferably of from 8 to 35 carbon atoms, or metal salts of such fatty acids; fatty alcohols corresponding to said acids; mono and polyhydric alcohol esters of said acids and corresponding amides; polyethylene glycols and methoxy-polyethylene glycols; terephthalic acids; and the like, reference column 7, lines 13 to 43.
Described in U.S. Pat. No. 4,367,275 are methods of preventing offsetting of electrostatic images of the toner composition to the fuser roll, which toner subsequently offsets to supporting substrates such as papers wherein there is selected toner compositions containing specific external lubricants including various waxes, see column 5, lines 32 to 45, which waxes are substantially different in their properties and characteristics than the polymeric alcohols selected for the toner and developer compositions of the present invention; and moreover, the toner compositions of the present invention with the aforementioned polymeric alcohol additives possess advantages such as elimination of toner spotting not achievable with the toner and developer compositions of the '275 patent.
Moreover, toner and developer compositions containing charge enhancing additives, especially additives which impart a positive charge to the toner resin, are well know. Thus, for example, there is described in U.S. Pat. No. 3,893,935 the use of certain quaternary ammonium salts as charge control agents for electrostatic toner compositions. There are also described in U.S. Pat. No. 2,986,521 reversal developer compositions comprised of toner resin particles coated with finely divided colloidal silica. Further, there are illustrated in U.S. Pat. No. 4,338,390, the disclosure of which is totally incorporated herein by reference, developer and toner compositions having incorporated therein as charge enhancing additives organic sulfate and sulfonate compositions; and in U.S. Pat. No. 4,298,672, the disclosure of which is totally incorporated herein by reference, positively charged toner compositions containing resin particles and pigment particles, and as a charge enhancing additive alkyl pyridinium compounds, inclusive of cetyl pyridinium chloride. Other prior art disclosing positively charged toner compositions with charge enhancing additives include U.S. Pat. Nos. 3,944,493; 4,007,293; 4,079,014 and 4,394,430.